Urinary catheterization is a routine procedure in the hospital and chronic care settings, and is associated with a significant risk of infection. The incidence of catheter-associated urinary tract infection approaches 50% after three days of continuous catheterization, according to some epidemiologic studies, and urinary tract infections account for the majority of nosocomial infections. Complications of urinary tract infection include bacteremia, pyelonephritis, antibiotic toxicity and renal failure, with resulting morbidity and mortality and direct costs exceeding $500 Million per year in the hospital setting alone.
In a closed sterile drainage system, bacteria can be transported from the urethral tip to the bladder during catheter insertion, and after catheter insertion migrate from the urethral tip to the bladder along the outside surface of the catheter shaft at its interface with the urethral mucosa. Prior art is replete with urethral catheters which deliver antiseptic materials to the urethra/catheter interface. U.S. Pat. No. 3,598,127 issued Aug. 10, 1971 to the name of James G. Wepsic, discloses a nonpermeable catheter tube with several peripherally located grooves filled with medicament, and a sheath covering the grooves which is permeable to the medicament. U.S. Pat. No. 4,623,329 presents a catheter tube and other permeable sleeve containing a concentric reservoir of antimicrobial fluid, the sleeve allowing controlled passage of the fluid to the catheter surface.
Other workers have altered the catheter tube surface composition to incorporate microbiocidal substances. U.S. Pat. No. 4,515,593 introduces a catheter comprised of hydrophobic elastomer and coated with a hydrophilic elastomer for incorporation of antimicrobial material. U.S. Pat. No. 4,539,234 disclosed a catheter composed of polymer base material with antimicrobial substance chemically bonded to the catheter wall.
Prior art urinary catheters have generally been designed for dispensing antimicrobial agents to the catheter surface. However, sliding movements of the catheter displace pathogens along the tube surface toward the bladder, and fluid motion may paradoxically expedite bacterial movement within the potential space between urethral mucosa and catheter surface. In addition, the chemical agent may not be sufficiently concentrated in areas of bacterial inoculation, and large inoculations from the urethral tip can circumvent such chemical barriers. In general, prior art catheters have been relatively complex in design and costly to construct, as well.
U.S. Pat. No. 4,784,647 introduces a foam pad treated with antimicrobial material which contacts the urethral meatus to minimize bacterial proliferation at this site. While colonization of bacteria is reduced, viable pathogens within the distal urethra can avoid contacting the antimicrobial agent and may access the bladder. Additionally, bacteria at the urethral tip and meatus could access the urethra and move proximally as contact between pad and meatus is interrupted during movements of patent and catheter (an antislip mechanism is provided in this invention to minimize interruptions in contact, however). Relatively large concentrations of bacteria at the urethral tip may challenge the barrier presented by the pad, with greater probability of success in bypassing it.
It is an object of the present invention to provide an antiseptic cuff for a urinary catheter for minimizing bacterial viability within the urethra, thereby preventing infection. A physical and chemical barrier to bacterial migration along a catheter tube surface is provided which also attenuates catheter movements within the urethra and is simply to manufacture and to apply.